A quantitative analysis of movement detecting neurons in the frog's retina

In the frog's retina (Rana esculenta, Rana pipiens) two classes of neurons which are especially sensitive to stimuli moved through the receptive fields were investigated. It was found that the following stimulus parameters determine the response of these class-2 and class-3 neurons: angular velocity (v), stimulus size (A), contrast of stimulus against a white or a black background (c), position of the path of traverse in the receptive field (P), and the time (t) between the movement of identical stimuli along the same path through the receptive field. These parameters were changed within a considerable range; the relation between the parameter change and the neuronal response is given in different equations. A final formula, which allows one to calculate the average response of a class-2 or a class-3 neurons to a stimulus moved through the excitatory receptive field is given in equations 6a and 6b.